Pneumatic tires require repair or replacement from time to time because of sustained wear or damage. To effectuate such repair or replacement, it is generally required that the defective tire be removed from its associate wheel rim and a new or repaired tire remounted to the rim.
A variety of tools of varying configurations have been developed for providing a user with mechanical advantage in mounting a tire to a wheel rim. Such tools typically comprise an elongate bar having a handle at one end and an opposite working end adapted for insertion between the bead of a tire and its associate wheel rim.
To utilize the implement, the tool working portion is inserted manually by the user between the bead of the tire and its associate wheel rim. Thereafter, the user applies pressure on the handle, making a lever of the tool and utilizing the wheel rim as a fulcrum. Pressure upon the handle causes the tool to engage the tire bead and move a segment of the bead inward, whereby disengaging the bead segment from the rim. The tool is then redeployed along the tire to an adjacent location, and the procedure is repeated upon a corresponding adjacent bead segment. Repeated redeployment and utilization of the tool about the periphery of the tire pulls a sufficient length of the tire bead inward until the tire is free for removal from the rim in its entirety. In more recent years, machines have been developed which rotate the tire in conjunction with the use of the tool to alleviate the need for moving the tool.
While the prior art is replete with mounting tools, the basic design has not changed significantly over the years. Known designs, while working well to an extent, have proven less than satisfactory in providing an optimally functional tire mounting implement. Some known devices mount tubeless truck tires by using separate tools for each tire bead. A first mounting tool is used to pull the first bead of the tire into the rim. Thereafter, a second mounting tool is inserted to press the second bead behind the rim to complete the mounting procedure. Separate implements, however, increase cost and complicate the tire changing procedure.
Other known designs use a straight bar having a tip that angles downwardly from the longitudinal plane of the tool. The downwardly-turned tip, while providing an advantage in creating a pronounced fulcrum, makes insertion of the tool between the tire bead and wheel relatively more difficult. Moreover, dislodging the angled tip of such a tool is frequently problematic and laborious. A further deficiency in such known tools is that their configuration does nothing to inhibit migration of the tire upwardly along the handle during use. With pressure being applied to the sidewall, the bead of the tire tends to move away from the rim and upward along the tool, decreasing the applied leverage of the tool. The profile of known straight tools does not inhibit this undesirable consequence.
A further deficiency exists in known tire mounting tools. To force the bead of a tire below a rim flange, a substantial segment of the sidewall must be compressed inward a significant extent. Such a deflection requires substantial force. To compensate, the user generally must progress about the tire in small increments, pressuring adjacent small portions or bites of the bead below the rim flange. As the user progressively moves the tool around the rim mounting the bead in a series of bites, the bead becomes progressively more taut and difficult to manipulate. Toward the end of the mounting process, the bead is extremely taut about the rim and difficult to manipulate, making insertion of the tool increasingly difficult. Known tools are typically difficult to insert and remove from between a taut tire bead and a wheel rim.
Moreover, known tools that incorporate a bend proximate the tire mounting tip experience a further difficulty. As the bend of the tool working end is pressed against the front edge of the bead to work the tool underneath the bead, the tool often catches on the rim flange. In order to avoid catching on the rim flange, the tool must be inserted by the user beneath the bead with the tool working end angled upward. Such an angle of insertion, however, is generally not available because the tool handle typically exceeds the rim diameter, and the handle cannot be brought below the level of the bead without striking the rim. Also, when mounting the first bead, the tool's radial progress is impeded by contact with the second bead. Finally, a further disadvantage exists in that the tool impinges against the sidewall of the tire during leverage activity.